1. Field of the Invention
The present invention relates generally to master links used in endless roller chain drives. More particularly, the invention relates to an improved master link having extended pins to receive a color coded extension plate for identification and safety purposes.
2. Description of the Prior Art
Many styles of roller chain drives have been developed. A master link is used to connect two ends of a roller chain together, creating an endless or continuous loop. In previously known master links, the idea of adapting the master link to contain a color coded extension pin link plate for both identification and safety purposes has never been implemented.
Color coded identification methods have been seen in other art fields. However, these methods are used in identifying different tools and not machinery components. Furthermore, other identification methods solve the problem of being unable to easily distinguish one known tool from another. The present invention solves the problem of not being able to easily and safely find a master link within an endless chain drive system.
U.S. Pat. No. 1,984,839 discloses an identification means for tools such as drills, reamers, and taps. The invention applies a color identification to the threads of a drill or to a recessed portion on the shank of the drill.
U.S. Pat. No. 2,915,926 discloses a color coded drill and reamer that has a matching color coded bushing. This invention seeks to avoid the unnecessary waste of time that is occasioned in matching tools with the corresponding bushings.
U.S. Pat. No. 4,671,916 discloses a method for identifying medical or surgical instruments as belonging to a group or set. The instruments are drilled to form a bore and then fitted with a plug for identification.
U.S. Pat. No. 4,841,653 discloses a method for identifying different types of wrenches. Color markings are applied to the wrenches through the application of a single band of colored tape to each tool.
In the present invention, color coding the extension pin link plate will allow the master link to be quickly identified. Different colors will indicate different chain sizes. However, the present invention also solves another problem that the prior art does not address. This is a problem involving chain drive repair and maintenance.
To repair or service a chain drive, it is first necessary to find the master link so that the chain may be removed. An ordinary master link closely resembles every other chain link. This makes it difficult to find the master link, especially when the chain can be ten or twenty feet long. Since the chain is often covered with grease, oil, and dirt, the difficulty is increased. Under these conditions, a repairman will need to reach into the machinery to wipe off part of the chain. It is then often necessary for the machine to be quickly turned on and off in order to move the chain into a slightly new position. This process of wiping the chain and operating the machine will continue until the master link is located.
This process often involves two people. A repairman will be reaching into the machine to wipe the chain and a second person will be standing at control panel, sometimes a distance away from the repairman. During this process, there is a possibility of the machine being accidentally operated while the repairman's hands and fingers are in contact with the chain, which may cause serious injury.
The present invention solves this problem. The pins of the master link are extended so that an additional extension pin link plate may be attached. The extension pin link plate is color coded so that it may be easily seen. In addition, since the master link now has longer pins, it is more visible when coated with grease, oil, and dirt. Therefore, the master link can be located without subjecting the repairman to the possibility of injury.